tmux: Support repeatable yank motions via yank.sh

Implementing logic inside tmux's config starts to become tedious with
growing complexity. Introduce a shell script that handles the logic of
the (now also repeatable) vim-like bindings.

.config/tmux/tmux.conf

@@ -132,23 +132,8 @@ bind -T copy-mode-vi C-v {
 	send -X rectangle-toggle
 }
 
-# Yank into system clipboard
-# TODO: This breaks on repeatable movements (e.g. `y2e`)
-bind -T copy-mode-vi y \
-	if -F "#{selection_present}" {
-		send -X copy-pipe
-	} {
-		command-prompt -k -p (operator-pending) {
-			# do line-wise yank on yy
-			if -F "#{==:%1,y}" {
-				send -X select-line
-			} {
-				send -X begin-selection
-				send "%1"
-			}
-			send -X copy-pipe
-		}
-	}
+# Yank into system clipboard with vim-like bindings
+bind -T copy-mode-vi y run-shell '${XDG_CONFIG_HOME:-$HOME/.config}/tmux/yank.sh'
 bind -T copy-mode-vi Y \
 	if -F "#{selection_present}" { send -X copy-pipe-line } { send -X copy-pipe-end-of-line }